Abstract: Purpose : The X- CT performance and surgical operation pathology to analyze 65 examples mediastinal part tumor's X -ray and CT performance, study the mediastinal part tumor's X-ray the elephant and CT the meaning that examine a patient. Materials and method : 65 cases mediastinal part tumor regulation for X -ray and CT, totally and inside 56 cases enhancement scan, contrast research analyzing tumor and CT performance characteristics, tally upping the X-ray and CT expressing of all. Result : Locating the mediastinal part tumor 49 example, locate the inside mediastinal part 9 example, locate the empress the mediastinal part 7 example. The appearance reports the oval 35 example, report the circular 21 example, report the anomaly 9 cases. The edge part reports the "arc-shaped" and calcified 5 examples, windpipe suffer to press 13 example. All manifestations of tumor 62 examples, part manifestation 3 cases. The boundary is clear 61 examples, density is even 29 examples, CT is worth 29~36 Hu. Report the low density 27 examples, CT is worth 8~20 Hu. Report the mixed density 10 examples, CT is worth 20~127 Hu. Now diagnosis mediastinal part tumor. Conclusion : Should contrast to combine together each other repair with the X-ray and CT, and is beneficial to getting decrease of false diagnosis, and as the first convenience of diagnosis.